Forced-draft grate.



T. HARLEY &'R. G. LONG.

r- FORCED DRAFT GRATB. i K APPLICATION FILED APBUVB, '1913. 1,088,094'. APatented Dee. so, uns.

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Patented `Dec. 30,l 1913;

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ttomag T. HARLEY R. G'. LONG.

FORCED DRAFT GRATB. APPLICATION FILED APE, 1913. 1,983,094. Patented Dec.30,1913.

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n u Y I fr llNl'lED STATEd PATENT @Flllha axiomas HARLEY ND Bonanno. LONG, vor LAWRENCE, KaNsAsrAssIoNoas To man U. s. MECHANICAL DRAFT COMPANY, or LAWRENCE, KANSAS, A Conronarron.

FORCED-DRAFT GRATE,

Losanna.

Specification 0f Letters Patent.

Patented Bee. 30, 3913.

Application med apra s, 1913. serial No. 759,687.

vented new and useful Improvements in l1`orced-Dralt Grates'f, of which the following' is a specification; 'i

This invention relates to improvements in the consti-action ot'thc bars of grates for use under forced dra tt natural draft in the tirebo-xes of furnaces', locomotives or the like and especially adapted for burning slack or tine coal, the invention consisting in the construction, combination and arrangement of devices hereinafter described and claimed.

The Object of this invention is to provide an improved form oi:` hollow` grate bar comprising a lower member and an upper member detachably secured together, the lower member being provided with valves which, when closed, form the bottom and adapt the bar for use under forced draft and when open adapt the bar for use under natural draft and eilect the discharge of ashes from within the bar, another object being to eilfectl improvements in the construction of the upper member whereby the same is provided with a series of detachable perforated plates which may be readily renewed when worn and which prevent undue expansion and contraction of the upper grate b ar member.

in the accompanying drawingst--Figure 1 is a fragmentary perspective view ot a furnace with its upper portion partly broken away and showing an improved forced draft grate constructed in accordance with our invention and arranged in the tirebox of the furnace. Fig'. 2 is a vertical longitudinal sectional view of the same. Fig'. 3 is a detail plan of several of Our improved grate bars, showing them arranged in operative relation to each ot-her. Fig. et is a vertical longitudinal sectional view of the same on the plane indicated by the line a-cz of Fig. 3, showing the valves which form the bottom of the grate bars in closed position. Fig. 5 is a similar view, showing,T the valves in open position. Fig. G is a detail plan view of one of the lower grate bar members, with its valves in closed position. Fig. 7 is a vertical transverse sectional view on the plane indicated by the line b-b of Fig. 3.

For the purposes of this specification, a portion oi furnace is indicated at 1 in Figs. 1 and @,which may be of any ordinary well-known constrattion and has the usual iirebox Q and ash pit 3. The 'rear wall i of the furnace is formed with a supporting flange 5. The front wall 6 is provided on its inner side with a supporting angle bar or flange bar 7. The 1grate bars 8 are arranged longitudinally between the Firebox and the ash pit, the rear ends of their lower members 9 restmg on the shoulder 5 andthe front lends of their lower members resting on the supporting' bar 7.

Each lower member 9 is hollow, open at its front-end as at l0, closed at its rear end as at 11 Open at its top and also at the bottom and the side walls 12 thereof have their lower portions formed with downwardly converging inwardly inclined 'beveleor shoulders 13 which are provided with upwardly opening recesses lll. Each recess is provided in its bottom at its rear end, with a bearingV notch 15. Flanges 16 are formed on the upper sides of the lower grate bar members and extend around the same and serve to retain the upper grate bar members 17 in place on the lower members, as will be understood.

AIn the bottom of each lower member Q'is a series otvalves 18 each ,valve being Vpron vided at its rear cornerslwith outwardly projecting journals 19 which are mounted in the bearing notches 15l of the lower grate bar member. The sides and ends of the valves are beveled so that when the valves are closed their beveled side edges lit closely against the bevel shoulders 13 ot the lower grate bar member and their beveled ends tit against one-another so that the' said valves close the bottom of the lower grate bar member and make the same substantially airtight. AThe rear end of the last valve in the series projects somewhat beyond its journals 119 as shown in Fig. 6 and is nar rowed as at 18 suiiiciently to enable it to olea-r the shoulders .13 and thus permit the operation of the valves.

Each valve 18 is provided at its rear end with a downwardly extending arm 20. The lower ends of the arms Q0 are pivotally con-- nected to operatiingr bars 21 and all ot the cp mating bars are pivotally connected at their 'Front ends to arms 22 of a rock shaft Q3 the said rock shaft. being mounted in bearings Ill@ either open or closed position.

areprovided in their rear wall with openings which discharge into the open front ends 10 of the lower gratefbarmcmbers 9.

A' suitable cut oil damper 29 is provided for the forced draft duct and by means of l5 which the forced draft riav bc regulated or cut otl`, as desired. Each upper member 17 is hollow, open at its lower and upper sides and closed at its` sides and ends and is of a size and shape adapting` its lower edge to be .20 fitted `on the lower member 9 and engaged fs-ides and ends ot the said openings are bev! and held in place by the flange 1G ol said lower member. The up 3er member 17 is provided at its upper side with cross bars 30, whereby openings 31 are formed and the eled and convergedownwardly so that each opening` is larger at its upper side than atits lower side. Plates 32 are detachably litted in the said openings and have their sides and ends correspondingly beveled so that `the plates are held in the opening and with their upper sides level with the tops of the upper grate bar members. These plates 32 are provided with draft slotsil?) which may 35 be arranged as here shown or otherwise, as

may be ineferred. ln order vto hold the vplates -32 securely and yet detaehably in place in the openings oit' the upper `frate bar meml'iers, metallic strips 34 are employed 40 which are secured to the vunder sides oi.E the said plates at their ends, by bolts 35 and engage the under side ot the cross bars 30 of the upper grate bar members. This construction of `the upper grate bar members enables them to expand and contract under varying degrees of temperature without becoming unduly warped or injured and greatly reduces theliability of fracture inci dentto such contraction and expansion, the

'plates 32 being fitted somewhat loosely in the openings 31 so that either the members 17. or the lates may expand and contract (Without a ecting the other.

When the damper in the, forced air duct QG is closed and the valves 185m the lower members of the grate bars are open, the furl nace is operated by natural draft.. `Wl1en the damper is open and the valves 18 are closed, forced draft from the duct 2G enters the front ends of the lower grate bar members through the openings 10 and passes up wardly through the upper grate bar members and the slots 33 of their detachable plates 32 so that forced draft is supplied to the fuel in all partsof the irebox and on the grate. The ashes drop through the slots 33 lon to the valves 18 when the latter are closed.

When it is desired to clean the grate bars, this is accomplished. by simply opening the valves 18 by the means hereinbefore described, thus causing the valves to, dump the ashes from -within -the grate bars, as Will be understood.

We claim 1. A hollow gratebar of the class described open at the bott-om and having its side walls provided with downwardly converging shoulders and a series of pivotally mounted valves in said bar arranged for vertical angular movement to open or close the bottom according to the position of the valves, said valves ,having beveled sides to fit between said shoulders when the valves are closed.

2. A hollow grate bar of the class described open at the bottom and having its side Walls provided with downwardly converging shoulders each having bearing notches in their upper sides, valves having` beveled sides to lit between the said shoulders and beveled ends to close against one another, the said valves being provided with pivoted journals mounted in the said bearing notches and being also provided with downwardly extending rock arms and an operating bar pivotally connected tothe said rock arms for simultaneously. actuating the said valves to move them to open or closed position;

In testimony whereot` we atlix our signalures in presence of two witnesses.

THOMAS HARLEY. ROBERT G. LONG \Vitnesses RAW-[OND F. Rien, C. O. BowMAN. 

